In some studies the average penis girth is measured at the three parts: under the head, the mid-shaft and the base. I am curious why they dont measure the head too or how we can what is the average penis girth at the base. Some people say that the base is thicker part of the penis. Do you have idea how many people have tha base thicker than the shaft and the head ( how many percent )?

I give suggestion to create a poll : what is your pre pe erect girth at the base , the mid-shaft girth, the girth under the head and the head girth.

For me I was just under 5" below the glans, around 5" midshaft, and about 5.5" base (never measured, when I started, so it may have been more. First time I did was a few months in and it was 5.75" I belive).
Now I'm 5.5" below the glans, 5.66" Midshaft, and 6.5" at the base.

I don't measure the head because it's just a pain. It's close to 6" for me.
I do think more people have a thicker base than anything.

I have a tree-trunk shaped penis, thickest at the base with a significant flare in the half inch closest to the pubic bone. I have always been this shape, but as Pegasus suggests, PE seems to have exaggerated the basal flare a little, although I have gained girth throughout.

I'm not sure this is universal, however, since I have heard many guys say that with jelqing they went from a cylindrical shape to a base ball bat shape.

The circumference of the glans is difficult to measure because of its shape and the fact that the plane of maximal circumference is typically not perpendicular to the long axis of the penis shaft. You can probably best measure the "effective" circumference of the glans by finding a tubular object that the glans will just fit into without compression and measuring its diameter. If you measure around the point of maximal circumference of the corona at an angle to the perpendicular, you will get a bigger measurement.

Different studies have used different standards for measuring penis girth. Some have used maximal girth and others girth around mid shaft. Sometimes the methodology is not spelled out, or sometimes one can even find conflicting information regarding how girth was measured in the same study. For example, in discussing the LifeStyles condom Cancun study the MrAverage site says this: Measuring of girth was at mid-shaft around the circumference of the penis when the penis was erect.

But the Wikipedia entry for human penis size discusses the same study and says this: The Cancún LifeStyle study, in which the circumference of the shaft was measured at three points (base, mid-shaft, and just below the head) and then averaged, found an average of 12.63 cm (4.972 inches) with a standard deviation of 1.3 cm (0.5 in).[10]

I have one more question. I can not find information about the circumference of the glans. Do you have some ideas how many percent have glans equal to the thickest part of the shaft and how many percent have bigger glans than thickest part of the shaft (base, mid-shaft, and just below the head)?